Excel Office 365 formulas

[Lilly Hughes]

How it happened I don't know. But when I create a formula or use a built-in formula such as Sum

I get this: 

=SUM(R[-2]C:R[-1]C)

How do I get it back to A1+B1

[#2]

@Lilly Hughes 

Excel for Windows:

Select File > Options,

Select Formulas in the navigation pane on the left.

Under 'Working with formulas', clear the check box 'R1C1 reference style'.

Click OK.

Excel for Mac:

Select Excel >Preferences

Select General.

Clear the check box 'Use R1C1 reference style'.

[#3]

@Hans Vogelaar  It worked. Thanks bunches.